On Fri, Nov 24, 2023 at 4:20 PM Alvin Šipraga <alvin@xxxxxxx> wrote:
>
> From: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
>
> The adv7511 driver is solely responsible for setting the physical
> address of its CEC adapter. To do this, it must read the EDID. However,
> EDID is only read when either the drm_bridge_funcs :: get_edid or
> drm_connector_helper_funcs :: get_modes ops are called. Without loss of
> generality, it cannot be assumed that these ops are called when a sink
> gets attached. Therefore there exist scenarios in which the CEC physical
> address will be invalid (f.f.f.f), rendering the CEC adapter inoperable.
>
> Address this problem by always fetching the EDID in the HPD work when we
> detect a connection. The CEC physical address is set in the process.
> This is done by moving the EDID DRM helper into an internal helper
> function so that it can be cleanly called from an earlier section of
> the code. The EDID getter has not changed in practice.
>
> Signed-off-by: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 74 ++++++++++++++++++----------
> 1 file changed, 48 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index 5ffc5904bd59..1f1d3a440895 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -542,6 +542,36 @@ static int adv7511_get_edid_block(void *data, u8 *buf, unsigned int block,
> return 0;
> }
>
> +static struct edid *__adv7511_get_edid(struct adv7511 *adv7511,
> + struct drm_connector *connector)
> +{
> + struct edid *edid;
> +
> + /* Reading the EDID only works if the device is powered */
> + if (!adv7511->powered) {
> + unsigned int edid_i2c_addr =
> + (adv7511->i2c_edid->addr << 1);
> +
> + __adv7511_power_on(adv7511);
> +
> + /* Reset the EDID_I2C_ADDR register as it might be cleared */
> + regmap_write(adv7511->regmap, ADV7511_REG_EDID_I2C_ADDR,
> + edid_i2c_addr);
> + }
> +
> + edid = drm_do_get_edid(connector, adv7511_get_edid_block, adv7511);
> +
> + if (!adv7511->powered)
> + __adv7511_power_off(adv7511);
> +
> + adv7511_set_config_csc(adv7511, connector, adv7511->rgb,
> + drm_detect_hdmi_monitor(edid));
> +
> + cec_s_phys_addr_from_edid(adv7511->cec_adap, edid);
> +
> + return edid;
> +}
> +
> /* -----------------------------------------------------------------------------
> * Hotplug handling
> */
> @@ -595,8 +625,24 @@ static void adv7511_hpd_work(struct work_struct *work)
> adv7511->connector.status = status;
>
> if (adv7511->connector.dev) {
> - if (status == connector_status_disconnected)
> + if (status == connector_status_disconnected) {
> cec_phys_addr_invalidate(adv7511->cec_adap);
> + } else {
> + struct edid *edid;
> +
> + /*
> + * Get the updated EDID so that the CEC
> + * subsystem gets informed of any change in CEC
> + * address. The helper returns a newly allocated
> + * edid structure, so free it to prevent
> + * leakage.
> + */
> + edid = __adv7511_get_edid(adv7511,
> + &adv7511->connector);
> + if (edid)
> + kfree(edid);
kfree(NULL) is safe, so the if statement can be removed.
With this fixed, feel free to add my r-b to this full series.
Reviewed-by: Robert Foss <rfoss@xxxxxxxxxx>
